Bananas for Scale
Big Boy Locomotive

Photo from Wikimedia Commons

Big Boy Locomotive

The largest steam locomotive ever built/Trains & Rail

The Union Pacific Big Boy is the largest steam locomotive ever built. Only 25 were manufactured between 1941 and 1944 to haul freight over the Wasatch Mountains. Each one is an absolute unit of riveted steel and controlled explosions. Big Boy No. 4014 was restored to operation in 2019 and remains the world's largest operating steam locomotive, delighting railfans and terrifying anyone standing too close to the tracks.

Measurements

Total length with tender40.5 m
5,063Ladybugs
14Condor wingspans
5.7 tenthsBoeing 747 lengths
Total mass with tender548,000 kg
1.4 millionCans of soup
18.9 billionGrains of rice

Loaded weight

Tractive effort4.7 million W
3,133Electric kettles
209 millionthsThree Gorges Dams

About 6,300 horsepower

Driving wheel diameter1.73 m
2.1 thousandthsBurj Khalifas
4.86Violins

68-inch drivers

Maximum speed36 m/s
72Shopping carts
2.31Charging grizzly bears
2.4Galloping horses

About 130 km/h

Coal capacity25,400 kg
84.7 octillionGlucose molecule weights
29,882Chipotle bowls
876 millionGrains of rice

28 tons in the tender

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